Tapping Quantum Effects for Software that Learns

Quantum calculation: At the center of this image, a series of prototype chips designed to use quantum mechanical effects to work with data.

In a bid to enable computers to learn faster, defense company Lockheed Martin has bought a system that uses quantum mechanics to process digital data. It paid $10 million to startup D-Wave Systems for the computer and support using it. D-Wave claims this to be the first ever sale of a quantum computing system.

The new system, called the D-Wave One, is not significantly more capable than a conventional computer. But it could be a step on the road to fuller implementations of quantum computing, which theoreticians have shown could easily solve problems that are impossible for other computers, such as defeating encryption systems by solving mathematical problems at incredible speed.

In a throwback to the days when computers were the size of rooms, the system bought by Lockheed, called the D-Wave One, occupies 100 square feet. Rather than acting as a stand-alone computer, it operates as a specialized helper to a conventional computer running software that learns from past data and makes predictions about future events. The defense company says it intends to use the new purchase to aid identification of bugs in products that are complex combinations of software and hardware. The goal is to reduce cost overruns caused by unforeseen technical problems with such systems, Lockheed spokesperson Thad Madden says. Such challenges were partly behind the recent news that the company’s F-35 strike fighter is more than 20 percent over budget.

At the heart of the D-Wave One is a processor made up of 128 qubits—short for quantum bits—which use magnetic fields to represent a single 1 or 0 of digital data at any time and can also exploit quantum mechanics to attain a state of “superposition” that represents both at once. When qubits in superposition states work together, they can work with exponentially more data than the equivalent number of regular bits.

Those qubits take the form of metal loops rich in niobium, a material that becomes a superconductor at very low temperatures and is more commonly used as the magnets inside MRI scanners. The qubits are linked by structures called couplers, also made from superconducting niobium alloy, which can control the extent to which adjacent magnetic fields, representing qubits, affect one another. Performing a calculation involves using magnetic fields to set the states of qubits and couplers, waiting a short time, and then reading out the final values from the qubits.